The Mystery of Light

[Guinevere]

Interesting ideas!
I have no explanation to contribute, only that I remember that in his poem "Mythopoeia" Tolkien is also using the "broken light" as a metapher, this time of Man's imagination, and in a positive sense:

man, subcreator, the refracted light
through whom is splintered from a single white
to many hues, and endlessly combined
in living shapes that move from mind to mind.